Cementing plug



Feb. 22, i938.

J. F. BLEE CEMENTING PLUG Filed OGt. lO, 1936 I /V VN TQ. E' 5,455.

stantially as shown in Fig. 1. A plurality of ribs I8 extend between the head I4 and the ring I5 and are attached to both for the purpose of holding these members in spaced relation.

A paper tube I9 extends between the head I4 and the ring I5. A canvas or fabric sheath 2U closely encircles the tube I9. 'Ihis canvas sheath is folded at a plurality of points, as shown at 2 I, and is placed together by the cord 22 to tightly encircle the paper tube I9. The cord 22 also extends across the ring I5, as shown at 23 in Fig. 4. The purpose of this arrangementof the cords II and 22 will be further described.

A plurality of arcuate plates 24 are placed on top of the ring I5 and these plates cover the joints in the ring. A solid disc 25 rests on top of the segments 24 and this disc is also formed of some frangble material.

The entire sealing packer is filled with successive layers of aggregate 2B, starting with coarse stone at'the bottom and terminating with ne sand at the top. The usual foot plug 2'1 in the casing is `provided with an annular blade 28 which is fastened to the top thereof.

In operation, the sealing plug-arranged substantially as shown in Fig. l-is rst lowered into the casing on the rope I3; the piston 2 is next inserted in the casing. Due to the length of the complete cementing plug, it is desirable to provide the iiexible connection I3 so that the sealing packer can be rst inserted and afterwards, the piston 2. When the piston is inserted in the casing, the cup 4 is expanded to tightly grip the casing with suflicient pressure so that the complete assembly will not drop into the well of its own weight. The mud pumps are now started and the cementing plug is gradually forced downwardly. When the foot plug 21 is reached, the blade 28 will engage and cut both of the cords I'I and 22. This permits immediate exp-ansion of the segmental ring I5 and this ring will then move outwardly and downwardly and will wedge into the space around the foot plug. When the cord 22 is severed, the folds 2| will extend whereupon the walls of the sealing packer will expand outwardly and tightly press against the casing. The aggregate within the sealing packer will then be distributed in a mass above the foot plug and yeven though drilling rnud should by-pass the piston, the character of the aggregate-consisting of fine to coarse particles--will form a mass irnpervious to the passage of the drilling mud. A positive seal is thus provided above the mass of cement which is arranged around and below the foot plug and the operator-due to the increase of pressure within the wall, will stop the mud pumps, and the cement will be allowed to harden. The paper tube I9 will burst when the canvas sheath expands, thus permitting the aggregate in the sealing packer to expand outwardly and to sift into all crevices or irregular corners, thus effectively sealing the casing, as previously described. The cement to which previous reference is made, is dumped into the well prior to running the cement plug as here described.

Having described my invention, I claim:

1. A cementing plug including a piston, a cup on the piston, a sealing pack-er below the piston, and a iiexible connection extending from the piston to the sealing packer whereby the piston and sealing packer are coupled together.

g 2. A cementing plug including a piston, a cup on the piston, a sealing packer below the piston, a flexible 'connection extending from the piston to the sealing packer whereby the piston and sealing packer are coupled together, said sealing packer containing an aggregate.

3. A cementing plug including a piston, a cup on the piston, a sealing packer below the piston, a flexible connection extending from the piston to the sealing packer whereby the piston and sealing packer are coupled together, said sealing packer containing an aggregate, said sealing packer beingA extensible transversely, and means automatically releasing said sealing packer for transverse distension.

4. A cementing plug including a piston, a rubber cup, an expansion block in the rubber cup, a sealing packer, exible means coupling the piston to the sealing packer, said sealing packer being filled with an aggregate.

5. A cementing plug including a piston, a rubber cup, an expansion block in the rubber cup, a sealing packer, flexible means coup-ling the piston to the sealing packer, said sealing packer being filled with an aggregate, the walls of said sealing packer being distensible, means holding said walls in contracted position, and automatic means to release said walls for distension.

6. A cementing plug including a sealing packer, a head, a bottom ring, a fabric sheath extending between the head and the ring, lacing extending longitudinally of the sheath, sheath being folded under the lacing, a means to sever said lacing whereby the sheath is permitted to expand, and an aggregate within the packer.

7. A cementing plug including a sealing packer,

said

a head, a bottom ring, a fabric sheath extending between the head and the ring, lacing extending longitudinally of the sheath, said sheath being folded under the lacing, a means to sever said lacing whereby the sheath is permitted to expand, an aggregate within the packer, said ring comprising a plurality of arcuate segments, and a cord wrapped around the segments whereby the ring is held in concentric position, said cord being severable by said means.

8. yA cementing plug including a sealing packer, a head, a bottom ring, a fabric sheath extending between the head and the ring, lacing extending longitudinally of the sheath, said sheath being folded under the lacing, a means to sever said lacing whereby the sheath is permitted to expand, an aggregate within the packer, and a paper tube arranged inside of the fabric sheath, said paper tube substantially the length of the sealing packerf f 9. A cementing plug including a sealing packer,

a head, a bottom ring, a fabric sheath extending between the head and the ring, lacing extending longitudinally of Athe sheath, said sheath being folded under the lacing, a means to sever said lacing whereby the sheath is permitted to expand, an aggregate within the packer, a piston including 'a rubber cup, means to extend said rubber cup, and flexible means connecting the piston and the sealing packer. f

10. A cementing plug including a sealing packer, a head, a bottom ring, a fabric sheath f mitted to expand, an aggregate within the packer, a paper tube arranged inside of the fabric sheath, said paper tube substantially the length of the sealing packer, a piston including a rubber cup,

means to extend said rubber cup, and flexible 5 means connecting the piston and the sealing packer.

JOHN F. BLEE. 

